fix environment variable search to be case insensitive

Author: jjw24

Plugins/Flow.Launcher.Plugin.Explorer/Search/EnvironmentVariables.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.IO;
@@ -18,12 +18,14 @@ internal static bool IsEnvironmentVariableSearch(string search)
 
         internal static Dictionary<string, string> LoadEnvironmentStringPaths()
         {
-            var envStringPaths = new Dictionary<string, string>();
+            var envStringPaths = new Dictionary<string, string>(StringComparer.InvariantCultureIgnoreCase);
 
             foreach (DictionaryEntry special in Environment.GetEnvironmentVariables())
             {
                 if (Directory.Exists(special.Value.ToString()))
                 {
+                    // Variables are returned with a mixture of all upper/lower case. 
+                    // Call ToLower() to make them look consitent
                     envStringPaths.Add(special.Key.ToString().ToLower(), special.Value.ToString());
                 }
             }
@@ -82,11 +84,12 @@ internal static List<Result> GetEnvironmentStringPathSuggestions(string querySea
 
             foreach (var p in environmentVariables)
             {
-                if (p.Key.StartsWith(search))
+                if (p.Key.StartsWith(search, StringComparison.InvariantCultureIgnoreCase))
                 {
                     results.Add(new ResultManager(context).CreateFolderResult($"%{p.Key}%", p.Value, p.Value, query));
                 }
             }
+
             return results;
         }
     }